var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');
var fs=require('fs');
let sqlQuery = require('./mysqlmodel/sql')
//引入session模块
let session = require('express-session');
var cookieParser = require('cookie-parser');
//引入上传模块
let multer = require('multer')

var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');



var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');
app.use(cookieParser('sessiontest'));
//配置session
app.use(session({
  secret: "sessiontest",
  resave:true,//强制保存session
  cookie:{
    maxAge:7*24*60*60*1000,//设置session的有效期为1周
  },
  saveUninitialized:true//是否保存初始化的session
}))
app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/login', indexRouter);
app.use('/users', usersRouter);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404));
});
app.all("*",function(req,res,next){
  //设置允许跨域的域名，*代表允许任意域名跨域
  res.header("Access-Control-Allow-Origin","*");
  //允许的header类型
  res.header("Access-Control-Allow-Headers","content-type");
  //跨域允许的请求方式 
  res.header("Access-Control-Allow-Methods","DELETE,PUT,POST,GET,OPTIONS");
  if (req.method.toLowerCase() == 'options')
     res.send(200); //让options尝试请求快速结束
  else
     next();
}),
// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

app.listen(4000, 'localhost',(err)=>{
  if(err){
      console.log('服务器启动失败');
      return;
  }
  console.log('服务器启动成功');
});

module.exports = app;
